Liriomyza biensis Boucher

Boucher, Stéphanie & Wheeler, Terry A., 2014, Neotropical Agromyzidae (Diptera) of the Mission Géodésique de l’Équateur: Becker (1920) revisited, Zootaxa 3779 (2), pp. 157-176 : 166-167

Liriomyza biensis Boucher sp. n.

( Figs. 28–31 )

Agromyza pusilla Meigen , of Becker (1920), in part.

Holotype ♂. Ecuador: Tulcan, Dr. G. Rivet 1902 ( MNHN).

Etymology. The species name is derived from the Latin bi (double) and ensis (sword), referring to the large spine on the surstylus and on the posteroventral margin of the epandrium. The name also reflects the similarity with the Nearctic species L. monoensis Spencer.

Diagnosis. This species can be distinguished from other Neotropical Liriomyza by the combination of a black palpus, an antenna that is mostly brown except for the first flagellomere which is yellowish basally and medially; brown femora that are paler ventrally, and characteristics of the male genitalia.

Description. Frons width 0.2 mm; ratio of frons width to eye width 1.7 (measured in dorsal view); orbit 0.23 times width of frons (including orbits) at midpoint; parafacial and cheek absent; 2 reclinate ors and 2 inclinate ori; orbital setulae reclinate, sparse; first flagellomere particularly small (one missing), and covered with short pubescence; arista approximately same length as maximum eye height with short but dense pubescence; gena deep, conspicuously extended at rear; gena height at midpoint: 0.30 times maximum eye height; clypeus narrow, with upper margin rounded; eye bare. One presutural and three postsutural dorsocentrals (but almost all setae missing); acrostichal setulae long, in about 6 irregular rows; prescutellar acrostichal seta absent; 2 notopleural setae; 1 strong postpronotal seta with 1 weaker one (about 1/3 length of strong seta); anepisternum with 1 strong seta on posterior margin a little above midpoint, and apparently 2 smaller setae; fore and mid tibiae without lateral seta; stridulatory mechanism present. Small species, thorax length dorsally (excluding scutellum): 0.6 mm. Wing measurement not possible (one wing missing and one damaged).

Colour. Frons and anterior orbit yellow; posterior orbit (especially along eye margin) brown to anterior ors; both vt on brown; hind margin of eye brown on dorsal half; face yellow; antenna brown, but first flagellomere yellowish basally and medially; palpus brown; upper margin of clypeus appearing mat. Mesonotum almost completely shining brown except for small yellow patch at hind corner; scutellum bright yellow centrally with brown patch laterally; basal scutellar seta on dark ground; postpronotum yellow with central brown patch; notopleuron mostly yellow but dark brown at junction with anepisternum; anepisternum narrowly yellow posteriorly (more so at posterodorsal corner); katepisternum mostly brown except upper margin yellow; calypter completely brown including margin and fringe; halter white; legs mostly brown, slightly paler ventrally; fore and mid-knees apparently yellowish (legs shriveled).

Male genitalia. Distiphallus narrowly separated from slightly shorter mesophallus; distiphallus parallel-sided, curving dorsally in lateral view ( Fig. 28 ); posteroventral margin of epandrium with strong spine ( Fig. 30 ); surstylus with long spine apically ( Fig. 30 ).

Comments. Becker (1920) mentioned that the five specimens identified as Agromyza pusilla Meig. (= Liriomyza pusilla (Meigen) , a Palaearctic and Oriental species) had slight differences in colour but that their general aspects were the same. Four of the specimens identified by Becker (1920) were examined and they represent four different species, including Liriomyza biensis . The other three specimens each represent different species of Liriomyza (listed below as species A, B and C) that are not formally described because available material is insufficient.

The phallus and surstylus are most similar to Liriomyza monoensis Spencer , known from California ( Spencer 1981), but the distiphallus appears narrower at the base in L. monoensis . The body colour of L. monoensis is also different, with the palpus, antenna and femora yellow, and the anepisternum entirely black.

Figures

FIGURES 28 – 31. Liriomyza biensis Boucher, (28) phallus, lateral. Inset shows freshly dissected specimen, (29) phallus, ventral. Inset shows freshly dissected specimen, (30) epandrium and surstyli, (31) ejaculatory apodeme. Scale bars = 0.05 mm.